This invention generally relates to refrigerant systems. More particularly, this invention relates to determining an amount of refrigerant charge within such systems.
These systems typically are charged at a factory or in the field after installation with an amount of refrigerant to provide adequate system performance for expected operating conditions.
It is possible for the system to lose refrigerant charge through damaged components or loose connections or to be inadequately charged at the factory or in the field. It is necessary to determine refrigerant charge loss to avoid interruptions in service for the customers and prevent a failure of the system components, such as a compressor.
Low refrigerant charge conditions typically do not become apparent until high demand conditions, at high ambient temperatures for example, when full load operation is required to provide the desired amount of cooling. If an inadequate amount of charge is not detected early enough, it leads to the loss of cooling capacity and may cause an interruption in service to the customer. Additionally, system components such as the compressor may malfunction or be damaged if there is an insufficient amount of refrigerant within the system.
It is necessary to diagnose a low refrigerant charge condition as early as possible to ensure adequate system performance and to avoid potential system component damage. Previously suggested techniques such as low suction pressure or evaporator coil freeze up detection can readily be mistaken for a different system malfunction such as evaporator airflow blockage, compressor damage, plugged distributor, indoor fan system failure or another problem. Differentiating between such system malfunction modes and an inadequate amount of refrigerant charge using known techniques requires exhaustive troubleshooting. Moreover, prior approaches do not provide low refrigerant charge amount information early enough to avoid possible component damage.
This invention addresses the need for making an early determination regarding the amount of refrigerant charge within the system.